<!DOCTYPE html>
<html>
<head lang="en">
    <meta charset="UTF-8">
    <title></title>
</head>
<body>
    <div style="position: absolute;left: 396.5px"></div>

    <script>

	var div = document.getElementsByTagName("div")[0];
	console.log(div.style.left);
	console.log(div.offsetLeft);
    </script>

</body>
</html>